SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ece92f4858d5a0a88ed1544cff87687ac5701c545c7caa022d6378389bbb1a06' 
  AND token = 'SDmmeCanT93jTm+1LTHxRbNBpSNGnWJtAkHFmxpBojE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}